Title: Extended Application State of Bulk Metallic Glasses and Some Novel Phenomena for High Entropy and Pseudo-High Entropy Glassy Alloys
Speaker: Prof. Akihisa Inoue
Date/Time: 2021.06.23 10:00-11:30
Location: Yiucheng Lecture Hall, Xu Zuyao Building
Inviter: Prof. Guangyin Yuan
Biography
Prof. Akihisa Inoue, a World-renowned material scientist, especially in the field of bulk metallic glasses, nano-cyrstals and quasicrystals. He received his PhD degree from Tohoku University, Japan, in 1975. He was a research associate from 1976 to 1985 in Institute for Materials Research, Tohoku University. In 1982-1984, he was a visiting researcher at Bell Laboratories, USA. In 1986 he was promoted to Associate Professor and in 1990 he was promoted to a full Professor in Tohoku University. From 2000-2005, he was a director of
Institute for Materials Research, Tohoku University, and in 2006-2012 he was selected to be a president of Tohoku University. He was selected to be a Life Member of the Japan Academy in 2006, and a U.S.A. National Academy of Engineering, Foreign Life Member in 2008. Prof. Inoue have received many important academic awards and honors in the world for his outstanding contributions to the progress of Materials Science, such as Japan Academy Prize (2002), Prime Minister Award, Industry-University-Government Cooperation Achievement(2006), The 2009 James C. McGroddy Prize for New Materials (American Physical Society), Acta Materiallia Gold Medal(2010), etc. Meanwhile, he was awarded the honorary doctorates by some top universities in the world, such as Honorary Doctorate, Royal Institute of Technology, Stockholm, Sweden(2005), Honorary Doctorate, Dong-Eui University, Korea(2007), Honorary Doctorate, and Shanghai Jiao Tong University, China (2011) ,etc. Prof. Inoue’s research interest focuses on the amorphous materials, quasicrystals and high entropy alloys, and has published over 2000 journal papers, which have been collectively cited more than 118000 times with an H-index 142, and he was awarded World top achievement ranking in Materials field in “A standardized citation metrics author database annotated for scientific field”, PLOS Biology, pp.1-6, August 12, 2019.
Abstract
Based on the finding of a wide supercooled liquid region before crystallization for multicomponent glassy alloys in 1988, bulk metallic glasses (BMGs) were synthesized by casting process for their new alloys in 1989. Subsequently, it was found in 1990 that Zr-based arc-melted alloy ingots can keep a glassy phase even in the slow cooling state on the copper hearth. Since then, much efforts have been devoted to the finding of new alloy compositions, clarifications of fundamental and unique properties and applications in conjunction with production process for BMGs. Nowadays, Fe- and Zr-based BMGs have gained huge application state as structural, magnetic and other functional materials and the commercial products in the case of Zr-based BMGs reach about hundred million pieces in a year.
As new metastable materials which were derived from multicomponent BMGs, high-entropy (HE) and pseudo-high entropy (PHE) alloys have attracted academic and engineering interests. When we look at the HE and PHE alloys, their alloys have been developed in the order of equiatomic BMGs in 2002, quiatomic fcc crystalline ribbons in 2004, nearly equiatomic HE bcc thin films in 2004, and then PHE BMGs in 2014. At present, these HE and PHE alloys have been major subjects in materials science and engineering fields. The present seminar aims to introduce (1) recent extended application state of Zr- and Fe-based BMGs, and (2) formation and some unusual phenomena of Zr-based PHE BMGs and late transition metal (Fe, Co, Ni)-based HE and PHE glassy alloys, and to investigate the future prospects of their metastable multicomponent alloys.